usrp n321通过GPS实现多设备时钟同步c代码
时间: 2023-10-27 15:05:56 浏览: 41
以下是使用GPS实现多设备时钟同步的C代码示例:
```c
#include <stdio.h>
<stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <uhd.h>
// Define the GPSDO reference clock frequency
#define GPSDO_REF_FREQ 10e6
// Define the GPS serial port
#define GPS_SERIAL_PORT "/dev/ttyUSB0"
// Define the USRP IP address
#define USRP_IP "192.168.10.2"
// Define the USRP reference clock frequency
#define USRP_REF_FREQ 10e6
// Define the USRP sampling rate
#define USRP_SAMPLING_RATE 10e6
int main(int argc, char *argv[])
{
// Initialize the USRP
uhd_usrp_handle usrp;
uhd_usrp_create(&usrp);
uhd_usrp_set_rx_antenna(usrp, "RX2");
uhd_usrp_set_rx_rate(usrp, USRP_SAMPLING_RATE, 0);
uhd_usrp_set_rx_freq(usrp, 1575.42e6, 0);
uhd_usrp_set_rx_gain(usrp, 30, 0);
uhd_usrp_set_time_source(usrp, "external");
uhd_usrp_set_clock_source(usrp, "external");
uhd_usrp_set_time_unknown_pps(usrp, 0, 0);
uhd_usrp_set_time_next_pps(usrp, uhd_time_now() + uhd_time_from_ticks(1e8, USRP_REF_FREQ), 0);
// Initialize the GPS
int gps_fd = open(GPS_SERIAL_PORT, O_RDWR | O_NOCTTY | O_SYNC);
if (gps_fd < 0) {
perror("Unable to open GPS serial port");
exit(1);
}
struct termios gps_options;
tcgetattr(gps_fd, &gps_options);
cfsetospeed(&gps_options, B9600);
cfsetispeed(&gps_options, B9600);
gps_options.c_cflag |= (CLOCAL | CREAD);
gps_options.c_cflag &= ~CSIZE;
gps_options.c_cflag |= CS8;
gps_options.c_cflag &= ~PARENB;
gps_options.c_cflag &= ~CSTOPB;
gps_options.c_cflag &= ~CRTSCTS;
tcsetattr(gps_fd, TCSANOW, &gps_options);
tcflush(gps_fd, TCIOFLUSH);
// Wait for GPS lock
char gps_buf[512];
int gps_lock = 0;
while (!gps_lock) {
int gps_bytes = read(gps_fd, gps_buf, sizeof(gps_buf));
if (gps_bytes > 0) {
if (strstr(gps_buf, "$GPGGA") != NULL) {
gps_lock = 1;
}
}
}
// Get the GPS time
char gps_time_buf[64];
int gps_time_lock = 0;
while (!gps_time_lock) {
int gps_bytes = read(gps_fd, gps_buf, sizeof(gps_buf));
if (gps_bytes > 0) {
strncpy(gps_time_buf, gps_buf, sizeof(gps_time_buf));
if (strstr(gps_buf, "$GPGGA") != NULL) {
gps_time_lock = 1;
}
}
}
char *gps_time_str = strtok(gps_time_buf, ",");
for (int i = 0; i < 1; i++) {
gps_time_str = strtok(NULL, ",");
}
double gps_time = atof(gps_time_str);
// Get the USRP time
uhd_time_spec_t usrp_time = uhd_usrp_get_time_now(usrp, 0);
// Calculate the time offset between GPS and USRP
double time_offset = gps_time - usrp_time.to_ticks(USRP_REF_FREQ);
// Set the USRP time
uhd_usrp_set_time_next_pps(usrp, usrp_time + uhd_time_from_ticks(time_offset, USRP_REF_FREQ), 0);
// Close the GPS serial port
close(gps_fd);
// Cleanup the USRP
uhd_usrp_destroy(usrp);
return 0;
}
```
注意:以上代码仅供参考,具体实现可能需要根据实际情况进行调整。同时,需要注意安全问题,例如在实际使用时需要添加权限验证等措施。